The invention relates to a dynamo for/on bicycles, comprising a housing receiving a stator and a rotor and securable to a bicycle, a drive member setting the rotor in rotary motion and being driven by a bicycle wheel.
Known dynamos of this type are attached to the bicycle fork and have a small wheel as a drive member, which rolls against the tire. The disadvantage thereof is that frequently rotation of the small wheel does not occur because of dirt or because of snow and ice, but rather the small wheel slips against the tire, so that no current can be generated. The possibility also arises of the fastening of the dynamo to the wheel fork becoming loose and the dynamo then getting between the spokes, which leads to accidents.
Furthermore, dynamos are known, which comprise a wide pressure roll, which also rolls against the tire. The same disadvantages of slip and a shortage of current generation also arise here.
Moreover, the drive members' rolling against the tire can damage the tire with prolonged use.
The problem on which the invention is based is that of providing a simply and economically constructed dynamo, which, on the one hand, can be attached securely to the bicycle and, on the other hand, achieves consistently certain and optimum transmission of motion from the bicycle wheel, but not from the tire, for current generation.